Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates generally to fluid flow systems. In one of its aspects, the invention relates to the control of fluid flow in a wind tunnel system.
2. Description of Related Art
Generally, the purpose of a wind tunnel is to measure the effect of the passage of a high velocity fluid, in this case air, over a body under controlled conditions. Such body may be an airplane, a building structure or an automobile.
In a wind tunnel, the prime consideration is to be able to control the velocity and the uniformity of the air flow. One very impractical method of doing this is to have a very long straight wind tunnel with the right combination of cross-sectional area and input wind generation power. This is impractical because each end of such a wind tunnel must be open to the atmosphere. Therefore, the common practice is to make the wind tunnel a loop so that no make up air is needed, debris can be prevented from entering the tunnel, energy is conserved, and other factors, such as air temperature, can be controlled.
In the past, it may have been a relatively simple matter of making a wind tunnel in a large loop. Perhaps the corners would be rounded, or perhaps some curved vanes would be placed in the corners to somewhat reduce the energy lost and the turbulence created in the corners. In a wind tunnel used only to determine forces of the wind on a body, and the aerodynamic effects, e.g. drag, on the body, the noise of turbulence occurring somewhere in the tunnel was less of an issue.
However, in a wind tunnel that is to be used for testing the acoustic effects of fluid flow over a body, the fluid flow must be xe2x80x9cpurifiedxe2x80x9d to isolate the acoustic effects created by the tunnel from those created by the flow of fluid over the test body itself. The goal is therefore to minimize the xe2x80x9cnoisexe2x80x9d generated by the wind tunnel itself. This xe2x80x9cnoisexe2x80x9d, from the testing standpoint, involves both the actual audible noise generated by a wind generator (fan/turbine) and the noise created by the turbulence of the fluid flow as it traverses the passageways, transitions and corners of the tunnel.
For the purposes of aerodynamic and acoustic evaluation of solid bodies, it would be advantageous to provide a wind tunnel assembly that minimizes the noise generated and attributable to the wind tunnel itself. It would also be preferable to reduce the energy lost to inefficient corners and transitions so as to reduce the power consumption required to generate a given capacity for air movement.
The present invention provides a diffusing corner for fluid flow within a fluid conduit, comprising a plurality of vanes arranged to divide the fluid conduit into a plurality of fluid passages, each of the plurality of vanes having a first surface and a second surface, the first and second surfaces being defined by non-circular sections, wherein the second surface of a first vane and the first surface of a second vane define one of the plurality of fluid passages, and wherein the plurality of vanes is arranged to direct the fluid flow through an angular displacement and an increase in cross-sectional area of the fluid conduit.